Valve-gear and governing mechanism for steam-engines.



Patented June 27, I899.

J.'B. ALLFREE. VALVE GEAR AND GOVERNING MECHANISM FOR STEAM ENGINES.v

I (Application filed Feb. 4, 1898.)

(No Model.)

mm W

UNITE STATES PATENT FFIGE. 7

JAMES B. ALLFREE, OF INDIANAPOLIS, INDIANA.

VALVE-GEAR AND GOVERNING MECHANISM FOR STEAM-ENGINES.

SPECIFICATION forming part of Letters Patent NO. 627,887, dated June 27,1899.

- Application filed February 4, 1898. Serial No. 669,053. (No model.) I

To aZZ whom it may concern:

Be it known that I, JAMEs B. ALLFREE, a citizen of the United States,residing at In dianapolis, in the county of Marion and State of Indiana,have invented certain new and useful Improvements in Valve-Gear andGoverning Mechanism for Steam Engines, of which the following is aspecification.

This invention relates to improvements in automatic slide-valve engines;and its object is to provide means whereby the valve can be opened andclosed at the ends of the stroke with an accelerated movement over thatwhich obtains at intermediate points, the present invention having thesame ultimate object as my former invention, for which I madeapplication for Letters Patent of the United States on June 7, 1897,Serial No. 639,713, and differs from it essentially in the use ofgearwheels in place of cams for varying the eccentricity of theeccentric.

I accomplish the objects of this invention by the mechanism illustratedin the accompanying drawings, in which Figure 1 is a detail in sideelevation of an engine, showing the governor-wheel equipped with myinvention and showing enough'of the related parts of the engineto maketheinvention fully understood. Fig. 2 is a side elevation of thegovernor-Wheel with my invention as illustrated in Fig. 1, but viewedfrom the opposite side of the wheel. Fig. 3 is a detail in cross-sectionon the line 3 3 of Fig. 1. Fig. 4 is a copy of an'indicator-diagram madeon an ordinary high-speed automatic engine, and Fig. 5 the copy of adiagram made from the same engine after it had been equipped with myinvention. Similar letters of reference indicate like parts throughoutthe several views of the drawings.

A represents a governor-wheel having the arms A, and B is a variableeccentric, all of which parts are of the usual construction. A hub a isformed on one side of the arms of the wheel or between'two of the armsand has a transverse bore in which a shaft 0 is mounted.

G is a pin,which is preferably integral with the shaft 0 and which iseccentric to the shaft. An eccentric plate or frame B, carrying theeccentric B, is pivoted-at one of its ends to The other end of the plateis con= This outward tendency will be counteracted by the spring F,which is connected at one end with the lever E and at its other end withthe slotted bar F. The bar F is fas-' tened to the wheel A. The shortarm of the lever E is connected by the link G with the frame B. I

H is the main shaft of the engine, on which the governor-wheel ismounted. The outer end of the shaft H is reduced to form the end h,which projects beyond the hub of the governor-wheel, and on this 1reduced end the spur gear-wheel I is mounted. The shaft 71. rotateswithin the wheel I; but the latter is held in a stationary position bythe handlebar J. A standard J, bolted to the frame of the engine and towhich the handle-bar is adj ustably secured, provides means for lookingthe wheel I against'rotation. v

K is a pinion one-half of the diameter of I the wheel I, which is keyedor otherwise fastened to the end of the shaft 0 oppositethat whichcarries the eccentric-pin C.

The length of the normal strokeof the valvedepends on the eccentricityof the eccentric due to the influence of the governor on said frame; butwith the construction as above described, in which the frame swings froma pin which is eccentric to a constantly-rotating shaft, it is obviousthat the eccentricity of the eccentric will be changed with everyrevolution of said shaft. The action of the eccentric-pivot will be,first, to accelerate the normal movement of the Valve and augment itsnormal maximum opening, and, second, to retard the movement of the valvein the same proportion that it had been previously augmented. Themechanism can be adjusted to make the maximum augmented openingcoincident with the end of the stroke of the valve, in which case thefull admission and exhaust of the steam would take place much nearer thebeginning of the stroke and its end, respectively, than heretofore and amuch wider opening would be secured with a quicker opening and closingof the valve.

By making the pinion K one-half of the diameter of the wheel I theeccentric-pivot will revolve twice with each revolution of thegovernor-wheel and the valve will be acted on alike at both ends of itsstroke, imparting to the valve a much more rapid movement at each endand a much slower movement throughout the middle portion of the stroke.By reason of this rapid travel at the ends of the stroke thesteam-openings may be made and closed with a much greater rapidity and awider opening obtained for an equivalent cut-off than is possible with asingle eccentric movement of the valve. It will thus be seen that theeffect of the auxiliary or modifying connections between thegovernor-Wheel and the eccentric is to cause a resultant motion, whichwill impart to the valve accelerated movements for quickly opening andclosing the admission and exhaust ports and retarded movements thatcause the valve to dwell or stop after the close of admission and beforethe close of exhaust, which retarded movements take place during themiddle portion of the travel of the valve. WVhen the eccentric-pin onthe wheel acts in conjunction with the eccentric, the resultant motionis an accelerated movement, and when the motions of the said pin andeccentric are opposed to each other the resultant movement is aretardation until the valve dwells'or stops or ceases to have effectivemovement at the points where such opposed motions are equal or nearlyequal.

By reason of its slower travel through the middle portion of its strokethe exhaust-valve remains closed longer before releasing the steam andcloses much later at the opposite end of the stroke, thereby materiallylowering the compression.

A comparison of the diagrams shown in Figs. 4 and 5 indicates at oncethe advantage and economy of my invention. The original diagram shown inFig. 4 was traced by an indicator on a high-speed automatic engine andshows the ordinary practice, and the original diagram shown in Fig. 5was taken from the same engine having the same valve and underconditions precisely similar to those existing when diagram 4 was taken,except that my improved valve mechanism herein described had been added.

The broad features of my invention herein disclosed, consisting of theuse of an auxiliary device or connection in combination with the primaryvalve-operating gear, so disposed asadmission and before the close ofexhaust, during each stroke of the piston, is notclaimed in thisapplication, as-such generic form of my invention is covered by myPatent No. 613,184, dated October 25, 1898; nor do I claim herein thecombination directly with the eccentric of an auxiliary or modifyingconnection between said eccentric and the governor-wheel, as that formsthe subject of my earlier application, Serial No. 639,713, filed June 7,1897, and While my present improvement is preferably applied to avariable or shifting eccentric it is obvious that it is not limitedthereto, as it may be applied to an ordinary eccentric as well.

Having thus fully described my invention, what I claim as new, and wishto secure by Letters Patent of the United States, is-

1. In an engine, the combination with the cylinder and valve, of arotating main shaft, a wheel mounted on said shaft, an eccentric carriedby the wheel and connected to the valve, a shaft journaled upon andrevolving with the wheel and connected eccentrically to its axis withsaid eccentric, and meansinterposed between the main shaft and saidshaft for continuously rotating said shaft in a given direction, thesaid parts being so arranged or disposed that the resultant motionimparted to the valve by said eccentric causes said valve to move withan accelerated speed during opening and closing of the ports, and

to dwell or stop after the close of admission and before the close orexhaust during each stroke, substantially as described.

2. A governor, a main or valve-operating eccentric connected with andgoverned in its eccentricity by said governor, an eccentricpin whereonsaid main eccentric is pivoted, said eccentric-pin having a rotationaround its own axis of rotation and also around the axis of rotation ofsaid main eccentric, sub stantially as and for the purposes specified.

3. A governor, a main or valve-operating eccentric connected with andgoverned in eccentricity by said governor, an eccentric-pin whereon saidmain eccentric is pivoted, said eccentric-pin having continuous rotationin one direction around its own axis of rotation and also rotation inthe same direction arou nd the axis of rotation of said main eccentric,substantially as described and for the purposes specified.

4. A governor,a variable eccentric connected with and changed ineccentricity by said governor, a slide-valve connected with theeccentric, an auxiliary eccentric having continu ous rotation around anaxis which rotates continuously around the, axis of rotation of thevariable eccentric, andmeans for connecting the two eccentrics,substantially as described and for the purposes specified.

5. A governor, avariable eccentric connected with and varied ineccentricity by said gow ernor, a slide-valve connected with theeccentric, a shaft traveling around the axis of the variable eccentricand having rotation on its own axis always in the same direction, saidshaft having an eccentric-pin, and means, substantially as described forconnecting the 'pin with the variable eccentric for the purposesspecified.

6. A revoluble shaft, a governor Wheel mounted thereon, a spurgear-wheel mounted on the other end of the shaft, a centrifugalgovernor, a variable eccentric connected with the governor, aslide-valve connected with the eccentric, a shaft traveling in a circlearound the axis of the variable eccentric and having an eccentric-pin, apinion on the end of the shaft opposite the eccentric-pin, said pinionmeshing with the spurgear-wheel, and means, substantially as described,for connecting the pin with the variable eccentric, for the purposesspecified.

7. A revoluble shaft, a governor Wheel mounted on said shaft, anon-revoluble spurgear mounted on the shaft-outside of thegovernor-Wheel, a second shaft parallel with the first and revolving ina circle around the axis of the first-mentioned shaft, a pinion on theend of the second shaft meshing with the gearwheel on the other shaft,an eccentric-pin on the end of the second shaft opposite the pinion, acentrifugal governor, a plate or frame pivoted at one end to theeccentric-pin and suspended at its other end from the governor andhaving an intermediate laterally-projected annular flange, aneccentric-ringmounted on said flange and a slide-valve secured to theeccentric, all substantially as described and specified. c

8. .The combination, with a rotating shaft, a governor-Wheel mounted onthe shaft, an eccentric, a governor-frame carrying the eccentric andoscillating around an eccentric pivot, a centrifugal governor connectedwith and operating the governor-frame, a pivot mounted eccentrically ona rotating shaft, a rotating shaft carrying an eccentric-pivot, a pinionmounted on and moving with the shaft which carries the eccentric-pivotand a spurgear twice the diameter of the pinion meshing therewith andheld in a fixed position", all substantially as described and for thepurposes specified.

In witness whereof I have hereunto set my hand and seal, atIndianapolis, Indiana, this 19th day of January, A. D. 1898.

JAMES B. ALLFREE. [L. s.] Witnesses:

- J OSEPH A. MINTURN,

THOMAS H. DAVIDSON.

